Blowout preventer for wells



M. E. TRUE BLOWOUT PREVENTER FOR WELLS Filed Dec. 2l, 1954 July 9, 1957 7 E@ Mw IN VEN TOR.

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United States Patent O s 2,798,561 nLowoUr PREVENTER non WELLS Martin E. True, Houston, Tex., assiguor, by mesne assignments, to Esso Research and Engineering Contpany, Elizabeth, N. J., a corporation of Delaware Application December 21, 1954, Serial No.47 6,7 07

9 Claims.v (Cl. 166--224) The present invention is directed to a blowout preventer. More particularly, the invention is directed to a subsurface blowout preventer forsautomatically shutting in wells. In itsfmore specific aspects, the invention is directed to a subsurface blowout preventer which will automatically shut in wells at a level in the well substantially below the level from which operations are conducted.

The present invention may be briefly described as a subsurface blowout preventer adapted to be connected into concentric pipe strings. The blowout preventer comprises arst mandrel provided with a first pressure chamb'er, the first mandrel being adapted to be connected into the tubingstring. Arranged in the first pressure chamber is a piston member having a piston arm connected thereto,` the piston arm extending into the interior of the mandrel and being provided with rack teeth on an intermediate portion thereof. A first valve member is arranged in the first mandrel to close off the passageway in the first mandrel and is operatively connected to the rack teeth on the piston arm by a gear segment.

A second mandrel adapted to be mounted in the well casingv coaxially with the first mandrel is provided with second and `third pressure chambers in which second and third piston members are arranged, respectively. Second and third piston arms provided with rack teeth on intermediate portions thereof are connected to the second and third pistons, respectively. A segmented Valve provided witha gear segment is operatively connectedlto the rack teeth on the second and third piston arms. The segmented valve member` is arranged in the second mandrel for operative sealing engagement with the first mandrel to close off the annulus between the pipes. The first, second and third pressure chambers are each connected to a source of pressure by -a pressure supply means which are suitably conduits extending to the earths surface to asource of' pressure located thereon. `The piston members in the first, second and third pressure chambers are normally biased to arst position by a biasing means arranged in the first, second `and third pressure chambers, respectively, pressure supplied to the pressure chamberstlnough the 'conduits forcingthe piston members to a second position to open the first valve and the first mandrel and to open the second valve to open up the annulus between the pipes.

` The present invention is of considerable vutility in marine4 locations where oil and gas well drilling takes place. If for any reason, the surface equipment which ordinarily controls an oil or gas well is damaged or broken off due to violent wave action from storms or by floating objects,t

reference to the drawing in which: L s I ice Fig. 1 is a front sectional View of a preferred embodiment;

Fig. 2 is a sectional view taken along the lines Z--Z of Fig. l;

Fig. 3 is a sectional view taken along lines 3--3 o Fig. 4 is a sectional view taken along the lines 4--4 of Fig. l; and

Fig. 5 is a sectional view taken along the lines 5-5 of Fig. l.

Referring now to the drawing, numeral 11 designates a' well casing arranged in a well bore as is conventional. Coaxially arranged within the casing 11 is a first tubing or pipe 12 and arranged within the first Itubing 12 is a second tubing string or pipe 13. The inner tubing string 13 is provided with a first mandrel or housing 14 which is connected to the tubingstring 13 by mating threads 15 and sealed thereto by a sealing means 16.

The mandrel 14 is provided with a pressure chamber 18 -in which is arranged a piston member 19 provided with sealing rings 20. Connected to the piston member 19 is a piston arm Z2 which defines with an intermediate portion thereof a rack 23 provided witha plurality of rack teeth 24, the piston arm 22 slidably extending into a bore 25 in the mandrel 14.

The piston chamber 18 is closed at its upper end by a plug 26 matingly connected by mating threads 27 to the mandrel 14. The plug 26 is provided with a bleed ori tice 28.

Frictionally bearing against piston member 19 and against the closure member 26 is a biasing means, such as a helical coil spring 29, which normally urges or biases the piston member 19 to a first position. Pressure is supplied to the pressure chamber 18 through a small conduit 30 which is adapted to extend to` the earths surface and connect to a source of fluid pressure located there. The conduit 30 connects to a longitudinal passageway 31 in the mandrel 14 by a threaded connection means 32. The longitudinal passageway 31, in turn, connects to a lateral passageway 33 and thence into the pressure chamber 18.

It is to be noted that the piston rod passes through the passageway 34 in the mandrel 14 and is sealed against leakage with sealing members 35.

Operatively connected to the rack teeth 24 of the rack 23 by a gear segment 37 isa valve 38 pivotally connected to the mandrel `14 by pivot 38a which serves to close off the passageway P in the mandrel 14 and tubing 13. The valve 38 is provided with an annular sealing member 39 arranged in a recess 40 in the valve 38 which fits against a shoulderor seating member 41 in the mandrel 14.

The mandrel 14 is suitably connected bv a sleeve 42 to a lower tubing joint 43 of the tubing string 13 by mating threads 44 and 45, the sleeve 42 being sealed by sealing members 46 and 47. The tubing joint 43 may be considered part of the mandrel 14 of reduced cross section.`

Connected into the outer tubing 12 by mating threads 50 is a second mandrel or housing 51 which is arranged coaxially with the first mandrel 14 and the tubing joint 43 which may form or be considered part of the mandrel The mandrel or housing 51 is provided with a plurality of pressure chambers 52 each of which has arranged therein a piston member 53 provided with piston rings or sealing members 54.

Connected to the piston members 53 are piston arms 56 which extend through passageways l57 in the housing ormandrel 51 and are arranged slidably in passageways 58 in the mandrel or housing 51. Forming an intermediate portion of the piston arms 56 are racks 59 provided with a plurality of rack teeth 60. lt is to be noted that the piston arms 56 are sealed in the passageways 57 by sealing members 61.

Pivotally connected by pivots 69 to the mandrel 51 are gear segments 70 which are attachedto and form part of split valve segments 72 which are adapted to engage sealingly'withV thetubing joint 43.

The valve segments 72 are each provided with annular sealing means 73 and 74 arranged, respectively, in recesses 75 and 76 of the valve segments 72. The sealing members v73 arev adapted to seat against seats 77 of the mandrel 51, while the sealing members 7e sealingly engage withA the tubing joint 43.

It is to be noted that the segments 72 make a tight fit witheach other and are wedged into engagement.

The pressure chambers 52 are each closed in with a closure means '78 each provided with a bleed orifice 79. Frictionally engaging with the closure member 78 and the piston members 53 in the pressure chambers 52 and bearing against the piston member 53 are biasing means or helical coil springs 78a which normally urge the piston members 53 to a first position. The pressure chambers 52 are supplied with pressure through a conduit 80 extendingk to the earths surface which is connected to each of the pressure chambers 52. The conduit 8f! has a branch conduit 81 which connects by a 'threaded connection S2 into theV pressure chamber 5. on the left side of Fig. 1 which, in turn, connects into a longitudinal passageway 86 in the mandrel 52 and thence by lateral passageway 84 into the chamber 52. The conduit 80 also connects into the pressure chamber 52 on 'the right side of Fig. l by a threaded connection 85 which connects into longitudinal passageways 86 and thence by lateral passageway 84 into the chamber 52 on the right side of Fig. 1. The passageways 86 being identical, only o'ne has been shown as in Fig. 5.

lt is to be noted that the mandrel 51 is threadably connected to the outer tubing 12 by mating threads 88; The valve segments 72 serve to close off the annulus A between the tubing 13 and the outer 'tubing 12 in a manner which will be described. In the embodiment of the drawing, the apparatus is shown in the closed position with the biasing means or helical coil springs 29 and '78a biasing Vthe piston members 19 and 53 to first positions to close off 'the passageway P in the inner tubing 13 and the annulus A between the inner tubing 13 and the outer tubing 12. When it is desired to open the passageway P and the annulus A pressure will be imposed in the passageway P and the annulus A sufficient to equalize pressure above and below the .valves 38 and 72. Pressure is then introduced into pressure chamber 18 and into pressure chambers S2 which forces the pistons 19 and 53 to second positions which cause the racks 23 and 59 to rotate the valves 38 and 72 and to open same, thus opening the passageway P and the annulus A.

When it is desired to control the well by closing the passageway P and |the annulus A, pressure will be released from pressure chamber 18 and from pressure chambers 52 by releasing the pressure at the well head either intentionally or accidentally which will cause the biasing means 29 and 78a to force the pistons 19 and 53 to the first positions which will rotate the valves 38 and valve 72 into closing engagement, as shown in the drawing.

In the present invention the well is controlled automatically such that the tubing and the casing-tubing annulus is closed off by releasing pressure on the pressure chambers. The valves serving to close the tubing passageway and the casing-tubing annulus are closed off automatically, the pressure in the tubing and annulus below the valves also serving to maintain the valves in closed position.

It will be seen from the foregoing description taken with the drawing that a subsurface blowout preventer has been provided in which a valve is mounted in the tubing string and a separate valve is arranged inthe tubing-casing annulus. The whole assembly is arranged in the well below the water or mud level or at a level substantially below the level Vfrom which operations are conducted to close off the tubing-casing annulus and the tubing.

As pointed out before in oil wells drilled in water locations, especially those offshore, it is important that means be employed to prevent blowouts in the event the surface equipment is damaged, severed, or blown ofir for any reason. Therefore, this invention is of considerable utility, both from a safety standpoint and from an economical standpoint.

The nature and objects of the present invention having been completely described and illustrated, what I wish to claim as new and useful and to secure by Letters Patent is:

l. A subsurface blowout preventer for concentric pipes adapted to close off the annulus between said pipes and to close off said inner pipe comprising a first mandrel connected in said inner pipe and a first pressure chamber formed thereon, a first piston slidably arranged in said pressure chamber having a first and second position and provided with a piston arm, said piston arm being provided with a first rack, first biasing means arranged in said first pressure chamber adapted to urge said first piston to said first position, a first valve member pivotally secured to said first mandrel and having teeth thereon engaging with said first rack, said first valve member being adapted to close off said first mandrel from uid tiow ytherethrough when said first piston is in said first position, a `first conduit connected to said first mandrel fluidly communicating said first pressure chamber with a source of Vfluid pressure, said fluid pressure being adapted to move said first piston against the bias of said first biasing means, a second mandrel connected in said outer pipe and havingv second and third pressure chambers formed thereon, second and third pistons slidably arranged in said second and third pressure chambers, respectively, said second and third pistons having first and second positions and being provided with second and third piston arms, respectively, said second and third piston arms having second andthird' racks provided thereon, respectively, second and third biasing means arranged in said second and third pressure chambers, respectively, adapted to urge said second and third pistons to said first positions, second and third valve members pivotally secured to said second mandrel, said second and third valve members having teeth thereon engaging with said second and third racks, respectively, said valve members being adapted to close off the annulus between said inner and outer pipes from fluid flow therethrough when said second and third pistons are in said first positions, a second conduit connected to said second mandrel luidly communicating said second and third pressure chambers with asource of fluid pressure, said fluid pressure being adapted to move said second and third pistons against the bias of said second and third biasing means, respectively.

2. A subsurface blowout preventer for concentric pipes adapted to close `off the annulus between said pipes and to close off said inner pipe comprising a first mandrel connected in said inner pipe and a first pressure charnber formed thereon, a first piston slidably arranged in said first pressure chamber having first and second positions and provided with a first piston arm, said piston arm being provided with a first rack, first biasing means arranged in said. first pressure chamber adapted to urge said first piston to said first position, a first valve member pivotally secured to said first mandrel and having teeth thereon engaging with said first rack, said first valve member being adapted to close off said first mandrel from fluid flow therethrough when said piston is in said first position, means connected to `said first mandrel fiuidly communicating said first pressure chamber with a source of fiuid pressure, said fluid pressure being adapted to move said first piston against the vbias of said first biasing means, a second mandrel connected -in said outer pipe and having second and third pressure chambers formed there on, second and third pistons slidably arranged in said second and third chambers,respectively, said second and third pistons havingfirst and second positions and being provided with second and thirdpistonvarms, respectively, said second and third piston arms having second and third racks, respectively,fprovided` thereon, second and third biasing means arranged in said second and third pressure chambers, respectively,`adapte`d to urge said second and third pistons to said first positions, second and sure being adapted to move said second and third pistons against the bias of said second and third biasing means, respectively.

3. A subsurface blowout preventer for concentric pipes adapted to close the annulus between said pipes and to close ofi said inner pipe comprising a first mandrel connected in said inner pipe and a first pressure chamber formed thereon, a first piston slidably arranged in said pressure chamber having a first and second position and provided with a piston arm, said piston arm being provided with a first rack, first biasing means arranged in said first pressure chamber adapted to urge said first piston to said first position, first valve means pivotally secured to said first mandrel and operatively engaging with said first rack whereby said valve means is actuated to open and close said first mandrel upon movement of said piston from said second to said first positions, means connected to said first mandrel fluidly communicating said first pressure chamber with a source of fiuid pressure, said fluid pressure being adapted to move said first piston against the bias of said first biasing means, a second mandrel connected in said outer pipe and having second and third pressure chambers formed thereon, second and third pistons slidably arranged in said second and third pressure chambers, respectively, said second and third pistons having second and third positions and being provided with said second and third piston arms, respectively, said second and third piston arms having second and third racks provided thereon, respectively, second and third biasing means arranged in said second and third pressure chambers, respectively, adapted to urge said second and third pistons, respectively, to said first positions, second and third valve means pivotally secured to said second mandrel and operatively engaging with said second and third racks, respectively, whereby the annulus between said pipes is closed and opened upon movement of said second and third pistons from said second to said first positions, means connected to said second mandrel fiuidly communicating said second and third pressure chambers with a source of fiuid pressure, said fiuid pressure being adapted to move said second and third pistons against the lbias of said second and third biasing means, respective y.

4. A subsurface blowout preventer for concentric pipes adapted to close off the annulus between said pipes and to close off said inner pipe comprising a first mandrel connected in said inner pipe and a first pressure chamber formed thereon, first piston means slidably arranged in said pressure chamber having :a first and second position and having first biasing means urging said first piston means to said first position, Ifirst valve means pivotally connected to said first mandrel operatively engaging with said piston means whereby movement of said piston from said first to :said second position actuates to move said valve means to close off said first mandrel, means connected to said first mandrel fiuidly communicating said first pressure chamber with a source of fluid pressure for supplying fluid pressure to move saiclpiston means from said first to said second position, a second mandrel connected in said outer pipe and having second and third pressure chambers formed thereon, second and third piston means slidably arranged in said second and` third pressure chambers having first and second positions and having second and third biasing means urging said` between said pipes, means connected to said second ,man-` drel fluidly communicating said second and third pressure chambers with a source of fluid pressure for supplying fluid pressure to move said second and third piston means, respectively, from said first to said second positions.

S. A subsurface blowout preventer for concentric pipes adapted to close off the annulus between said pipes and to close off said inner pipe comprising a first mandrel connected in said inner pipe having a first pressure chamber formed` thereon, a second mandrel connected in said outer pipe having second and third pressure chambers formed thereon, first, second and third piston means slidably :arranged in said first, second and third pressure chambers, respectively, first valve means connected to said first mandrel adapted to close oli said inner pipe, second and third valve means connected to said second mandrel adapted to close off the annulus between said pipes, said first, second and third valve means engaging with said first, second and third piston means, respectively, whereby movement of said pistons actuates said valves and means connected to each of said pressure chambers fiuidly communicating with a source of fiuid pressure for supplying fiuid pressure to said pressure chambers to move said pistons to close ofi said inner pipe and the annulus between said pipes.

6. A subsurface blowout preventer for concentric pipes adapted to close the annulus between said pipes, comprising a mandrel connected in said outer pipe and having first and second pressure chambers formed thereon, first and second pistons slidably arranged in said first and second pressure chambers, respectively, said first and second pistons having first and second positions and being provided with first and `second piston arms, respectively, said first and second piston arms having first and second racks, respectively, provided thereon, first and second biasing means arranged in said first and second pressure chambers, respectively, adapted to urge said first and second pistons to said first positions, first and second valve means pivotally secured to said mandrel and operatively engaging with said first and second racks, respectively, whereby the annulus between said pipes is closed and opened upon movement of said first and second pistons from said second to said first position, means connected to said mandrel fiuidly communicating said first and second pressure chambers with a source of fluid pressure, said fiuid pressure being adapted to move said first and second pistons against the bias of said first and second biasing means, respectively.

7. A subsurface blowout preventer for concentric pipes adapted to close off the annulus between said pipes, comprising a mandrel connected in said outer pipe and having first and second pressure chambers formed thereon, first and second piston means slidably arranged in said first and second pressure chambers having first and second positions and provided with first and second biasing means urging said first and second piston means, respectively, to said first positions, -first and second valve means arranged on said mandrel and engaging with said first and second piston means, respectively, whereby movement of said first and second piston means from said first to said said first and second pressure chambers with a source of fluid pressure for supplying fluid pressure to move said 5 rst and second piston means, respectively, from said rst to said second positions.

l8. A subsurface blowout preventer for concentric Apipes adapted to close off the annulus between said pipes, comprising a mandrel connected in said outer pipe having 10 first 'and second pressure chambers formed thereon, irst and `second piston means sldably arranged in said rst and second pressure chambers, respectively, first and second valve means connected to said mandrel adapted to close off the annulus 'between said pipes, said rst and second valve means 4engaging with said rst and second piston'means, respectively, whereby movement of said pistons actuates said valves, and means connected to each of said pressure chambers fluidly communicating with a sourcelof fiuid pressure for supplying uid pressure to said pressure chambers to move `said pistons to close off the annulus Abetweenrsaid pipes.

9. Apparatus as recited Vin claim 8 wherein said valve means .comprise segments provided with sealing means adapted to sealingly engage .said inner pipe when said annulus is closed off from fluid ow therethrough.

References Cited in the le of thisrpatent UNITED STATES PATENTS 2,080,610 Humason s May 18, 1937 .2,104,660 Long etal. Jan. 4, 1938 2,207,944 'Richardson July 16, 1940 2,504,006 Davis Apr. 11, 1950 2,592,325 Otis et a1. Apr. 8, 1952 

1. A SUBSURFACE BLOWOUT PREVENTER FOR CONCENTRIC PIPES ADAPTED TO CLSE OFF THE ANNULS BETWEEN SAID PIPES AND TO CLOSE OFF SAID INNER PIPE COMPRISING A FIRST MANDREL CONNECTED IN SAID INNER PIPE AND FIRST PRESSURE CHAMBER FORMED THEREON, A FIRST PISTON ARM BEING SAID PRESSURE CHAMBER HAVING A FIRST AND SECOND POSITION AND PROVIDED WITH A PISTON ARMM BEING PROVIDED WITH A FIRST RACK, FIRST BIASING MEANS ARRANGED IN SAID FIRST PRESSURE CHAMBER ADAPTED TO URGE SAID FIRST PISTON TO SAID FIRST POSITION, A FIRST VALVE MEMBER PIVOTALLY SECURED TO SAID FIRST MANDREL AND HAVING TEETH THEREON ENGAGING WITH SAID FIRST RACK, SAID FIRST VALVE MEMBER BEING ADAPTED TO CLOSE OFF SAID FIRST MANDREL FROM FLUID FLOW THERETHROUGH WHEN SAID FIRST PISTON IS IN SAID FIRST POSITION, A FIRST CONDUIT CONNECTED TO SAID FIRST MANDRAL FLUIDLY COMMUNICATING SAID FIRST PRESSURE, SAID CHAMBER WUTH A SOURCE OF FLUID PRESSURE,SAID FLUID PRESSURE BEING ADAPTED TO MOVE SAID FIRST PISTON AGAINST THE BIAS OF SAID FIRST BIASING MEANS, A SECOND MANDREL CONNECTED IN SAID OUTER PIPE AND HAVING SECOND AND THIRD PRESSURE CHAMBERS FORMED THEREON, SECOND AND THIRD PISTON SLIDABLY ARRANGED IN SAID SECOND AND THIRD PRESSURE CHAMBER, RESPECTIVELY SAID SECOND AND THIRD PISTONS HAVING FIRST AND SECOND POSITION AND BEING PROVIDED WITH SECOND AND THIRD PISTON ARMS, RESPECTIVELY, SAID SECOND AND THIRD PISTON ARMS HAVING SECOND AND THIRD RACKS PROVIDED THEREON, RESPECTIVELY, SECOND AND THIRD BISASING MEANS ARRANGED IN SAID SECOND AND THIRD PRESSURE CHAMBER, RESPECTIVELY, ADAPTED TO URGE SAID SECOND AND THIRD PISTONS TO SAID FIRST POSITTIONS, SECOND AND THIRD VAVLE MEMBERS PIROTALLY SECURED TO SAID SECOND MANDREL, SAID SECOND AND THIRD VALVE MEMBERS HAVING TEETH THEREON ENGAGEING WITH SAID SECOND AND THIRD RACKS, RESPECTIVELY, SAID VALVE MEMBERS BEING AND THE THIRD PISTON ARE IN SAID FIRST POSITIONS, A SECOND OUTER PIPES FROM FLUID FLOW THERETHOUGH WHEN SAID SECOND AND THIRD PISTONS ARE IN SAID FIRST POSITIONS, A SECOND CONDUIT CONNECTED TO SAID SECOND MANDREL FLUIDLY COMMUNICATING SAID SECOND AND THIRD PRESSOURE CHAMBERS WITH A SOURCE OF FLUID PRESSURE, SAID FLUID PRESSURE BEING ADAPTED TO MOVE SAID SECOND AND THIRD PISTON AGAINST THE BIAS OF SAID SECOND AND THIRD BIASING MEANSM RESPECTIVELY. 